[krbdev.mit.edu #2147] Debug output hooks need to be added to support Windows Help Desk

[Jeffrey Altman via RT]

The old windows krb4 library provided debug output which could be used
by Help Desks to debug misbehaviors.  The lack of this functionality in
the krb5 libraries is a serious problem.

If there is time it would be good to add some debugging to the krb5
libraries at critical points such as kdc name resolution; send to kdc;
and the cache ticket retrieval functions.